Earlier criticism of the carrier's lax maintenance and inspection practices, for which the airline had been fined $7.5 million in 2008, was quickly echoed.[3] An NTSB spokesman said the hole was limited to 14 by 17 inches, due to the design of the aircraft.[4]

The NTSB investigation into the incident confirmed that metal fatigue was the cause of the crack;[5] specifically, that the damage was caused by pre-existing fatigue cracks that began at the edge of metal sheets on the inner surface of the aircraft's skin.[6]